From 8ad3b93fed1bdd601993b73a600f4d176f755c68 Mon Sep 17 00:00:00 2001
From: Dean Sheather <dean@deansheather.com>
Date: Wed, 2 Aug 2023 02:07:45 +0000
Subject: [PATCH 1/3] fix: avoid infinite loop in agent derp-map

---
 codersdk/agentsdk/agentsdk.go | 7 ++++---
 enterprise/coderd/coderd.go   | 2 +-
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/codersdk/agentsdk/agentsdk.go b/codersdk/agentsdk/agentsdk.go
index f4b114438c010..e8cde1a65b90e 100644
--- a/codersdk/agentsdk/agentsdk.go
+++ b/codersdk/agentsdk/agentsdk.go
@@ -211,13 +211,11 @@ func (c *Client) DERPMapUpdates(ctx context.Context) (<-chan DERPMapUpdate, io.C
 			if err != nil {
 				update.Err = err
 				update.DERPMap = nil
-				return
 			}
 			err = c.rewriteDerpMap(update.DERPMap)
 			if err != nil {
 				update.Err = err
 				update.DERPMap = nil
-				return
 			}
 
 			select {
@@ -225,14 +223,17 @@ func (c *Client) DERPMapUpdates(ctx context.Context) (<-chan DERPMapUpdate, io.C
 			case <-ctx.Done():
 				return
 			}
+			if update.Err != nil {
+				return
+			}
 		}
 	}()
 
 	return updates, &closer{
 		closeFunc: func() error {
 			cancelFunc()
-			_ = wsNetConn.Close()
 			<-pingClosed
+			_ = conn.Close(websocket.StatusGoingAway, "Listen closed")
 			<-updatesClosed
 			return nil
 		},
diff --git a/enterprise/coderd/coderd.go b/enterprise/coderd/coderd.go
index fcd9b5a6550d2..5487cb76d93d5 100644
--- a/enterprise/coderd/coderd.go
+++ b/enterprise/coderd/coderd.go
@@ -768,7 +768,7 @@ func derpMapper(logger slog.Logger, cfg *codersdk.DeploymentValues, proxyHealth
 				EmbeddedRelay: false,
 				RegionID:      regionID,
 				RegionCode:    regionCode,
-				RegionName:    status.Proxy.Name,
+				RegionName:    status.Proxy.DisplayName,
 				Nodes:         nodes,
 			}
 		}

From c5e8083766a56444584d2ab585d5bd596c4bee45 Mon Sep 17 00:00:00 2001
From: Dean Sheather <dean@deansheather.com>
Date: Wed, 2 Aug 2023 02:09:21 +0000
Subject: [PATCH 2/3] fixup! fix: avoid infinite loop in agent derp-map

---
 enterprise/coderd/coderd.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/enterprise/coderd/coderd.go b/enterprise/coderd/coderd.go
index 5487cb76d93d5..c3cc5e0be5ccd 100644
--- a/enterprise/coderd/coderd.go
+++ b/enterprise/coderd/coderd.go
@@ -706,6 +706,10 @@ func derpMapper(logger slog.Logger, cfg *codersdk.DeploymentValues, proxyHealth
 			// existing ID in the DERP map.
 			regionID := int(startingRegionID) + int(status.Proxy.RegionID)
 			regionCode := fmt.Sprintf("coder_%s", strings.ToLower(status.Proxy.Name))
+			regionName := status.Proxy.DisplayName
+			if regionName == "" {
+				regionName = status.Proxy.Name
+			}
 			for _, r := range derpMap.Regions {
 				if r.RegionID == regionID || r.RegionCode == regionCode {
 					// Log a warning if we haven't logged one in the last
@@ -768,7 +772,7 @@ func derpMapper(logger slog.Logger, cfg *codersdk.DeploymentValues, proxyHealth
 				EmbeddedRelay: false,
 				RegionID:      regionID,
 				RegionCode:    regionCode,
-				RegionName:    status.Proxy.DisplayName,
+				RegionName:    regionName,
 				Nodes:         nodes,
 			}
 		}

From 96ad4d3315266eed1621e63e5a44298c2218bccc Mon Sep 17 00:00:00 2001
From: Dean Sheather <dean@deansheather.com>
Date: Wed, 2 Aug 2023 02:20:43 +0000
Subject: [PATCH 3/3] fixup! fix: avoid infinite loop in agent derp-map

---
 codersdk/agentsdk/agentsdk.go | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/codersdk/agentsdk/agentsdk.go b/codersdk/agentsdk/agentsdk.go
index e8cde1a65b90e..7f66c01bc864b 100644
--- a/codersdk/agentsdk/agentsdk.go
+++ b/codersdk/agentsdk/agentsdk.go
@@ -212,15 +212,22 @@ func (c *Client) DERPMapUpdates(ctx context.Context) (<-chan DERPMapUpdate, io.C
 				update.Err = err
 				update.DERPMap = nil
 			}
-			err = c.rewriteDerpMap(update.DERPMap)
-			if err != nil {
-				update.Err = err
-				update.DERPMap = nil
+			if update.DERPMap != nil {
+				err = c.rewriteDerpMap(update.DERPMap)
+				if err != nil {
+					update.Err = err
+					update.DERPMap = nil
+				}
 			}
 
 			select {
 			case updates <- update:
 			case <-ctx.Done():
+				// Unblock the caller if they're waiting for an update.
+				select {
+				case updates <- DERPMapUpdate{Err: ctx.Err()}:
+				default:
+				}
 				return
 			}
 			if update.Err != nil {